Method and apparatus for the ultrasonic treatment of a dilute alcoholic solution

ABSTRACT

An apparatus for the ultrasonic treatment of dilute alcoholic solution in which a vibrator member placed in a dilute alcoholic solution is subjected to ultrasonic vibrations to produce cavitation in the solution in such a way that alcohol in the solution is vaporized and collected in a high concentration. The alcohol may be readily converted into a corresponding aldehyde.

This is a division of application Ser. No. 646,062, filed Aug. 31, 1984now U.S. Pat. No. 4,599,459.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a method for the ultrasonic treatment of adilute alcoholic solution in which the alcohol is vaporized from thedilute alcoholic solution.

2. Description of the Prior Art

Ultrasonic vibrations have been heretofore used to oscillate vibratorsin water, with the result that cavitation is produced thereby generatingsteam. Alternatively, ultrasonic vibrations are utilized to be acted onliquors in order to facilitate removal of froth from beer or aging ofwhisky. However, ultrasonic vibrations have never been utilized forvaporization of alcohol without causing cavitation.

In the fermentation of alcohol, when a concentration of alcohol reachesa certain level, e.g. about 12%, the alcohol productivity of yeastfungii is suppressed. In recent years, alcohol-resistant fungii havebeen discovered but even with such fungii, the alcohol productivity issuppressed when the alcohol concentration exceeds 15%. About 10% to 20%of carbohydrates added to a fermentation mother liquor remainsunfermented. Especially, when starting starchy materials aresaccharified with aspergilli and are subsequently subjected to alcoholicfermentation by means of yeast fungii as with Sake, about 50% of theadded starchy materials is left as sake lees in the form of dextrin,cellulose and starchy materials. This arises problems from thestandpoint of saving resources and preventing ecological pollution.Moreover, it is generally accepted that for the production of alcoholicliquors having high concentrations by distillation of the liquorsobtained by filtration of the fermentation liquor, about 7.5 liters ofpetroleum as fuel per 10 liters of the alcohol product is required.Additionally, a cooling energy which is used to cool and condense oncevaporized alcohol is not negligible. It is known that production ofalcohol having a high concentration requires petroleum in the sameamount as the alcohol.

It is also known that for the production of aldehydes such asformaldehyde, acetoaldehyde and the like, organic and inorganic mercurycompounds which involve environmental pollution problems are used.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a method for theultrasonic treatment of dilute alcoholic solutions which overcomes thedrawbacks of the prior art and in which an alcohol solution having ahigh concentration can be produced from a dilute alcoholic solution byvaporizing the alcohol therefrom by the use of only a slight energy.

It is another object of the invention to provide a method for theultrasonic treatment of dilute alcoholic solutions which enables one tocarry out continuous alcoholic fermentation without lowering aconcentration of starting materials in the fermentation system.

It is a further object of the invention to provide a method for theultrasonic treatment of dilute alcoholic solutions from which aldehydescan be produced in a very simple manner without use of any organic orinorganic mercury compounds, thus not involving any environmentalpollution problems.

The above objects can be achieved, according to the invention, by amethod for the ultrasonic treatment of a dilute alcoholic solution whichcomprises placing a vibrator member in a dilute alcoholic solution, andsubjecting the vibrator member in the dilute alcoholic solution toultrasonic vibration to cause cavitation whereby the alcohol in thesolution is vaporized.

BRIEF DESCRIPTION OF THE DRAWING

A sole FIGURE is an illustrative view of an apparatus for carrying outthe method of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made to the accompanying drawing which illustrates anembodiment according to the invention. In the FIGURE, indicated at 10 isa fermenter, at 11 is a tank for starting material from which a startingmaterial is fed into the fermenter, at 12 is microfilter which isassociated with the tank 11 and serves to prevent various bacteria fromentering, at 13 is a agitator blade for agitating a mother liquor 90being fermented in the fermenter 10, and at 15 is a motor for drivingthe agitator blade. Around the fermenter 10 are provided a heater and acooling water circulator (both not shown) so that the temperature of thecontent is kept at a given temperature of, for example, about 30° C.

Indicated at 16 is an ultrasonic processor having a container 17 whichis in the form of a dish at the lower portion thereof and in the form ofan inverted cone at the upper portion and is made, for example, ofstainless steel. The processor 16 further includes a vibrator member 20which is ultrasonically vibrated on reception of a signal current froman ultrasonic wave generator 18. Moreover, the processor 16 is toarranged that the mother liquor 90 in the fermenter 10 is circulated, asa dilute alcoholic solution 91, by means of a circulation pump 21through pipes 22, 23. Indicated at 25 is a connection port through whichan inert gas is fed. The connection port 25 is connected to a bomb (notshown) of an inert gas such as carbon dioxide, nitrogen, helium,hydrogen or the like and the gas is discharged from an inlet port 26placed in the ultrasonic processor 16, thereby forming an inert gasatmosphere. Of these gases, carbon dioxide is preferred.

In general, the ultrasonic processor 16 may not be directly connected tothe fermenter 10. The dilute alcoholic solution 91 accomodated in thefermenter may be methyl alcohol, ethyl alcohol, propyl alcohol, butylalcohol or the like. With the apparatus shown in the figure, thealcohol-fermented mother liquor, a supernatant liquid of the motherliquor, or a filtrate obtained by filtration of the mother liquor may befed to the processor 16. The vibrator member 20 may be a quartzvibrator, a barium titanate ceramic vibrator, a nickel ferrite vibrator,a magnetostrictive metal vibrator, or a member provided in the container17 and integrally combined with the above-mentioned vibrators located atthe outside of the container 17. The vibrator member 20 is oscillated bymeans of the ultrasonic wave generator of 10⁴ to 10⁷ Hz.

Cavitation is produced by ultrasonically vibrating the vibrator member20 very slightly under conditions where the pressure in the ultrasonicprocessor 16 is initially, transiently reduced, so that the alcohol inthe solution 91 is vaporized. Once the cavitation takes place, so-calledintoxication is produced and thus even though the inner pressureincreases due to the vaporization of the alcohol, the cavitationcontinues. Upon occurrence of the cavitation, the alcohol is vaporizedand the solution 91 moves upwards at the above portion of the vibratormember 20 as shown. The vaporized alcohol is fed through a pipe 27connected with the container 17 at the upper end thereof. Indicated at28 are a plurality of bumping-preventive perforated plates which arevertically spaced from one another in such a way that the holes of therespective plates are not superposed, by which the bumping of thesolution 91 in which the solution jumps as a liquid column at the upperportion of the container 17 is properly prevented. The electric powerrequired for the vaporization of the dilute alcoholic solution 91 bycavitation caused by ultrasonic vibrations is mucn smaller than the casewhere the vaporization is by heating. If large ultrasonic vibrations aregiven to the vibrator member 20, even water may be vaporized by theresulting cavitation. On the other hand, slight ultrasonic vibrationslead to vaporization of the alcohol alone.

Indicated at 30 is solid matter-adsorption and condensation column inwhich the vaporized alcohol fed through the pipe 27 is adsorbed andcondensed. In the column are filled powder moldings such as carbon blackor active carbon, fluorine resin powder moldings, fluorinated graphitepowder moldings, fluorinated graphite fibers and the like. The column isarranged to be cooled by means of cooling water, but an arrangement maybe used in which no cooling water is used. Indicated at 33 is areservoir for receiving a liquefied, highly concentrated alcohol 92passed through the solid matter-adsorption and condensation column 30.The reservoir is provided with a cooling means and cooled. At 35 is adischarge port from which the alcohol from the reservoir 33 isdischarged. Indicated at 36 is a vacuum tank evacuated through a vacuumpump 37. The tank 36 is connected to the reservoir 33 and used to reducethe pressure within the ultrasonic processor 16. In general, when thecavitation is kept continued, a valve 38 is closed. If necessary, thevacuum pump 37 may be continuedly operated in order to reduce thepressure within the ultrasonic processor 16. Indicated at 40 is anothersolid matter-adsorption and condensation column provided between thevacuum pump 36 and the reservoir 33 and having the same construction asthe column 30. This column serves to liquefy the alcohol vaporizing inthe reservoir 33 at the time of vacuum suction, thus preventing thevaporized alcohol from entering the vacuum tank 36, followed byreturning to the reservoir 33 as drain. Indicated at 41 is a gaschromatography which is automatically controlled by a sensor provided atthe upper portion of the column 42. From the information of the sensorare determined an amount and a quality of the gas. If, for example, thevaporized alcohol is large in amounts, the output level of theultrasonic generator 18 can be lowered. Indicated at 43 is a blower forcirculating the inert gas and the alcohol vapor within the reservoir 33to the ultrasonic processor 16. After the inert gas has been once fed tothe ultrasonic processor 16, the blower may stop further feed of theinert gas and serves to liquefy the vaporized alcohol. The inert gasatmosphere is necessary in order to prevent troubles such as formationof aldehydes, explosion and deflagration by oxidation reaction of thevaporized alcohol with gas phase oxygen or oxygen dissolved in thesolution 91.

It has been found that if no inert gas atmosphere is present in theultrasonic processor 16, the alcohol vaporized by the cavitation isoxidized with gaseous oxygen and oxygen dissolved in the solution 91into aldehydes. However, if the solution 91 which is free of dissolvedoxygen is fed, it is possible to produce alcohol alone.

In the practice of the invention, if the vibrator member 20 isultrasonically vibrated within the ultrasonic processor 16 to producecavitation while feeding oxygen in a properly controlled concentrationsuch as by adding carbon dioxide to compressed air, for example, fromthe connection port 25 to have a low oxygen concentration, the vaporizedalcohol is oxidized. The oxidation is pronouncedly facilitated by thecavitation with ready formation of aldehydes. The aldehydes areaccomodated in the reservoir 33. In this connection, a solid catalystmay be provided near the bumping-preventive plates 28 in the ultrasonicprocessor 16 for complete conversion into aldehydes. When using methylalcohol, ethyl alcohol, propyl alcohol and butyl alcohol as the dilutealcohol solution 91, there are, respectively, obtained formaldehyde,acetoaldehyde, propylaldehyde, and butyladlehyde.

As described above, in the practice of the invention, the vibratormember 20 which is placed in the dilute alcoholic solution 91 isultrasonically vibrated to produce cavitation, by which the alcohol isvaporized. The alcohol can be vaporized at higher efficiencies than thecase where the solution 91 is directly heated for vaporization, thusmaking it possible to save the energy consumption.

Moreover, because no distillation under heating conditions is carriedout, koji and yeast fungii surviving in the dilute alcoholic solution 91are not killed or enzyme is not decomposed. Accordingly, where thealcoholic solution 91 is circulated from the fermenter 10 toward theultrasonic processor 16, unfermented carbohydrates can be completelyconverted into alcohol. In addition, to the single fermenter 10 isappropriately added the starting material consisting of a thermallysterilized thick mother liquor from the tank 11 in order not to lowerthe concentration of the starting material, thereby enabling continuousfermentation of alcohol.

When aldehydes are produced in accordance with the present invention, noorganic or inorganic mercury compounds are necessary and thus they canbe prepared very simply without involving any problems of environmentalpollution.

The present invention is more particularly described by way of examples.

EXAMPLE 1

A Langevin-type quartz vibrator (1.7 MHz, input power 20 W) was used andacted on 300 ml of a 10% ethyl alcohol solution. In an atmosphere ofcarbon dioxide, the initial pressure in the ultrasonic processor wastransiently reduced to 700 mmHg to produce cavitation, causing alcoholvapor to be gushed for about 3 minutes. The vapor was introduced intothe solid matter-adsorption and condensation column, thereby obtainabout 25 ml of a 87% ethyl alcohol solution

EXAMPLE 2

Using the apparatus shown in the figure, 200 liters of a fermentationmother liquor of 15% theriac to which yeast fungii was added was placedin the fermenter 10 and fermented for 6 hours. Thereafter, thecirculation pump 21 was operated to introduce the mother liquor into theultrasonic processor 16. By the fermentation, the gas phase in thecontainer 17 was a carbon dioxide atmosphere but in order to ensuresafety and prevent oxidation of vaporized alcohol, a small amount ofcarbon dioxide was added. Initially, the vacuum pump 37 was operated sothat the pressure of the vacuum tank 36 was reduced. Simultaneously withthe operation of the ultrasonic processor 16, the container 17 wasreduced in pressure. Ultrasonic vibrations of 20 KHz with an input powerof 500 W (maximum output of about 200 W) were used. Under theseconditions, the ultrasonic processor 16 started to be operated andcavitation was thus produced, followed by stationary operation. Forinitial one hour, 8 liters of 85% ethyl alcohol was obtained and acontinuous operation of 10 hours resulted in 40 liters of ethyl alcohol.

EXAMPLE 3

A Langevin-type quartz vibrator (1.7 MHz, input power 50 W) was used toproduce cavitation in 500 ml of 10% ethyl alcohol solution. As a result,40 ml of 78% acetoaldehyde solution was obtained in the reservoir 5minutes after commencement of ultrasonic vibrations.

What is claimed is:
 1. An apparatus for the ultrasonic treatment of adilute solution of a lower aliphatic alcohol, said apparatuscomprising:a means operable for contacting a solution of lower aliphaticalcohol with a means for generating ultrasounds, wherein the said meansfor generating ultrasounds comprises a vibrator member operable forcontacting a dilute alcoholic solution whereby a portion of the saidsolution is vaporized; a means for detecting the quantity and quality ofa part of the said portion being vaporized, said means for detectingcontrolling said means for generating ultrasounds; and a means forcondensing and liquefying the vaporized portion.
 2. The apparatus ofclaim 1, wherein the said apparatus comprises a fermentation means forthe production of said dilute solution of a lower aliphatic alcohol,said fermentation means being in communication with said apparatus. 3.The apparatus of claim 1, said apparatus comprising a means operable forcirculating a dilute solution of a lower aliphatic alcohol from the saidfermentation means to the said contacting means.
 4. The apparatus ofclaim 1, wherein the ultrasounds are produced by a vibrator membervibrating within a frequency range of 10⁴ to 10⁷ Hz.
 5. The apparatus ofclaim 4, wherein the vibrator member comprises one of a quartz vibrator,a barrium titanate ceramic vibrator, a nickel ferrite vibrator, or amagnetostrictive metal vibrator.
 6. The apparatus of claim 2, whereinsaid fermentation means is operable to produce a lower aliphatic alcoholwhich is at least one member selected from the group consisting ofmethyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol.
 7. Anapparatus for the ultrasonic treatment of a dilute solution of a loweraliphatic alcohol, said apparatus comprising:a means operable forcontacting a solution of lower aliphatic alcohol with a means forgenerating ultrasounds, wherein the said means for generatingultrasounds comprises a vibrator member operable for contacting thedilute alcoholic solution whereby a portion of the said solution isvaporized; a first solid-matter-adsorption and condensation column forabsorbing, condensating and liquefying the vaporized lower aliphaticalcohol; a reservoir for receiving the liquefied alcohol fed through thematter-adsorption and condensation column; a vacuum tank incommunication with said apparatus and a vacuum pump in communicationwith said vacuum tank and operable to evacuate said vacuum tank; asecond solid-matter-adsorption and condensation column provided betweensaid reservoir and said vacuum pump; a means for detecting the qualityand quantity of vaporized lower aliphatic alcohol in said secondsolid-matter-adsorption and condensation column; a means for feeding anelectric current to said vibrator member, said means feeding theelectrical current in accordance with the quantity of vaporized loweraliphatic alcohol detected by the gas detecting means; and a blower forrecyclying a gas, in communication with said apparatus.